In the mobile communication system including a mobile phone, a radio wave state between a base station and a mobile terminal is influenced by an environment of an object such as buildings, vegetation, and cars, and usage frequency of the system. Therefore, a designer of a wireless network needs to perform measurements in order to appropriately grasp the radio wave state of the service area when a large change is caused in the state of the building or when a large change is caused in the number of users and traffic. Moreover, even when a detectable change as above is not recognized, it is preferable to periodically measure the radio wave state.
The measurement of the radio wave state is performed by using a measurement vehicle mounted with an antenna and a measurer for measuring receiving field intensity and a GPS (Global Positioning System) for measuring the current position, and driving within a measurement area. Such measurement requires approximately one to two days even when measuring an area of a few square km as a measurement team goes the site and drives on roads in the measurement area in a meshed manner. Further, the measurement team requires a navigator to guide a driving route and an engineer who operates the measurer besides a driver who drives the measurement vehicle. Therefore, in the measurement of the radio wave state by the measurement vehicle, there has been a problem to be solved that it requires high personal expenses.
In order to solve such problem, PTL 1 discloses a system that measures the radio wave state of the service area using radio wave information reported from a mobile terminal such as a mobile phone terminal used by a general user. This system has a function that indicates the measurement area and measurement time to perform radio wave measurement to a mobile communication network, calculates electric field intensity distribution for different areas and time zones using reception level data or the like transmitted from the mobile terminal, and displays it on a map.
In such radio wave measurement using the mobile terminal, when performing measurement at a high frequency such as every minute to all the mobile terminals, the information to be reported will be enormous besides that the power consumption of the terminal increases, thus the process will be difficult. Accordingly there has been attempts to solve such problem by limiting an area and time to perform the measurement. For example, in the radio wave state measurement system disclosed in PTL 1, by connecting a weather information system, a network monitoring system, and a traffic measurement system, it is possible to grasp the state of radio waves at the time when a change of the weather state or an equipment failure is caused. Moreover, in a weather forecast server disclosed in PTL 2, by searching for a mobile phone placed in an area which runs short of weather information and receiving the weather information from the mobile phone, efficient collection of the weather information is performed.